The -modified flag causes guru to read a simple archive file from stdin.
This archive specifies alternative contents for one or more file names.
The build.Context checks this table before delegating to the usual
behavior.
This will not work for files that import "C" since cgo accesses the
file system directly.
Added end-to-end test via Emacs.
Simplify findQueryPos (now: fileOffsetToPos)
Credit: Daniel Morsing, for the prototype of this feature.
Change-Id: I5ae818ed5e8bb81001781893dded2d085e9cf8d6
Reviewed-on: https://go-review.googlesource.com/19498
Reviewed-by: Daniel Morsing <daniel.morsing@gmail.com>
e08a7ae6bc